Quality of master impressions and related materials for fabrication of complete dentures in the UK

The aim of this study was to examine the quality of master impressions and related materials for fabricating complete dentures in the UK. One hundred and fifty pre-piloted questionnaires were distributed to a number of dental laboratories in the UK with large catchment areas. Information requested related to the quality and choice of techniques for the master impression stage of fabricating complete dentures, as well as prescription of materials for occlusal registration, amongst others. All information was recorded anonymously. One hundred and forty-four completed questionnaires were returned. All items were provided on a private basis. Eighty-three per cent (n=119) of master impressions were made using a custom tray, the remainder were made using a plastic stock tray. The most commonly used impression material was zinc oxide-eugenol (42%, n=60), followed by polyvinylsiloxane (39%, n=56) and irreversible hydrocolloid (19%, n=28). Master casts were poured after a minimum of 4 days. Eleven per cent of impressions examined (n=16) were judged to have errors. It was reported that 64% of master impressions (n=92) examined had been disinfected adequately. While this study revealed evidence of good clinical practice, particularly in relation to the selection of impression trays and quality of master impressions for complete dentures, there were some areas of concern, particularly in relation to the disinfection of the impressions examined. Dental practitioners should aim to provide their patients with high-quality prostheses by observing best clinical practice at all times.